It comes despite opposition from protestors who have branded the project at the Postwick junction as an over-engineered gateway to the controversial northern distributor road.

Protesters aired their views during the ceremonial event yesterday, organised by Norfolk County Council to mark the start of the work.

Made up of groups Friends of the Earth, Stop Norwich Urbanisation, Campaign to Protect Rural England and members of the Green Party, a handful of objectors stood with a banner, while council chairman Hilary Cox broke the soil with a gold spade.

Richard Bearman, leader of the Green group at County Hall said: “We don’t believe the alleged growth would be good for Norwich.”

But Andrew Proctor, leader of Broadland District Council, said the growth and the infrastructure needed to support it was necessary.

“We are trying to grow the economy and we need to create jobs and housing,” he added. “This is everything we need to make a thriving community.”

Construction work on the improvement of the A47 Postwick junction, at the eastern end of the Norwich bypass, will start on Monday and currently work on site clearance, archaeology and utility diversions is being carried out.

The scheme was first allocated government funding five years ago. Since then a start on site has been delayed by legal challenges to the planning consent, a change of government, and a public inquiry into the slip road and side road Orders, which were finally approved by the secretaries of state earlier this year.

As well as releasing land for 1,600 homes, the county council says it will unlock some £80m of private investment and the potential for 5,000 jobs.

Representatives of the main contractor Birse Civils, part of Balfour Beatty, engineering consultants Mott MacDonald, the Highways Agency, and NCC’s Postwick development and construction team also attended the event.

• What do you think of the plans? Write to Letters Editor at Prospect House, Rouen Road, Norwich, NR1 1RE.• What do you think of the plans? Write to Letters Editor at Prospect House, Rouen Road, Norwich, NR1 1RE.